The present invention relates to a medicine, drink, food and feed which is having an action of strengthening bone. The medicine, drink, food or feed combined with collagen, fraction containing collagen, and/or degradation product that has effects of promoting bone formation, strengthening bone,preventing and treating bone metabolic diseases such as osteoporosis, bone fracture, bone pain and so on.
Accompanying the prolongation of the human life span, the incidence of metabolic bone diseases such as osteoporosis, bone fracture, bone pain etc., has recently increased. In bone tissue, bone formation and bone resorption are always occurring. While the balance of bone formation and bone resorption is kept in one""s youth, bone resorption exceeds bone formation due to various causes as one""s age increases (uncoupling). And when bone resorption persists for a long duration, bone tissue becomes fragile, which causes metabolic bone diseases such as osteoporosis, bone fracture, bone pain, etc.
As conventional methods of preventing or treating metabolic bone diseases by inhibiting uncoupling include (1) calcium supplemented diets, (2) light exercise, (3) sunbathing, (4) medicinal therapy, etc. As for calcium supplemented diets, calcium salts such as calcium carbonate, calcium phosphate, etc., and naturally occurring calcium-containing preparation, such as bovine bone powder, egg shell, fish bone powder, etc. are used. They are, however, not necessarily good enough for oral intake. As light exercises, jogging or walking may be recommended. However, they are troublesome to a person who becomes weak and quite difficult to an immobilized aged person. Sunbathing is believed to be good for supplementing the active form of vitamin D3 but is not sufficient. As medicinal therapy, 1 xcex1-hydroxyvitamin D3 and/or calcitonin may be used and they are known to be effective for treating osteoporosis. However, these medicines can not be used as food sources.
On the other hand, collagen is known as a main protein component of animal connective tissue and occupies nearly 30% of total protein in mammalian, especially, human whole body. This collagen is a protein of cellular matrix and can be defined to be a substance having an xcex1-chain which is a helical portion consisting of 3 polypeptide chains and forming a multi-molecular complex. Further, collagen forms intercellular matrix with glyco-proteins, such as proteoglycan, fibronectin, laminin etc., and is an essential component for exhibiting its function as assembled tissue of cells in multi-cellular biological organism.
The present inventors have investigated to find a substance capable of strengthening bone which is useful for food sources. Eventually, we found out that a fraction containing collagen such as skin protein fraction or bone protein fraction has an effect of promoting proliferation of osteoblast. Further, the present inventors found that degradation products of an the fraction containing collagen also have an effect of promoting proliferation of an osteoblast and accomplished the present invention.
Accordingly, an object of the present invention is to provide a medicine, drink, food or feed having an action of strengthening bone. More specifically, the present invention is to provide a medicine, drink, food and feed having an action of strengthening bone combined with collagen, fraction containing collagen and/or degradation product thereof.
Another object of the present invention is to provide a medicine, drink, food or feed combined with collagen, fraction containing collagen or degradation product thereof which is further combined with calcium and vitamins.
As a fraction containing collagen used in the present invention, skin protein fraction, bone protein fraction, lyophilization product of pulverized and skim corium layer, lyophilization product of pulverized and decalcified bone, and fraction which is produced by treating skin protein fraction or bone protein fraction with acid or alkaline can be exemplified. Further, a degradation product which is produced by hydrolysis with a proteolytic enzyme and has a molecular weight of 2-150 kDa can be used.